Dark-light change of iris parameters and related factors among American Caucasians, American Chinese, and mainland Chinese

Abstract

Purpose: To assess the distribution of dark-light changes in iris features and associated factors amongst American Caucasians, American Chinese and mainland Chinese aged 40 years and over. Methods: Four gender- and age-matched cohorts: Caucasians, American Chinese, Southern Chinese and Northern Chinese comprised the study population. Anterior segment optical coherence tomography (ASOCT) images were acquired under dark and light conditions. Customized software was used to calculate iris thickness at 750 μm from the scleral spur (IT750), iris curvature (ICurv), iris area (IArea), and pupil diameter (PD) from ASOCT images. Results: Data from 121, 124, 121 and 120 subjects were available for Ame..